The Balkan country is targeting a fiscal shortfall of 1.0 percent of gross domestic product this year after ending 2017 with a surplus of 0.9 percent mainly due to increased pensions and teacher wages.
Sofia has pegged its lev to the euro and needs to run conservative fiscal policy to protect the economy from external risks.
"The mid-term perspective is linked to the priority to maintain the stability of public finances and outlines the fiscal goals for continued fiscal consolidation," the ministry said in a statement.
The economy is expected to expand by 3.9 percent this year, after growing by 3.6 percent in 2017, the finance ministry said, adding that a weaker domestic demand will lead to a slower growth after 2018.
It expects public debt, one of the lowest in the European Union, to gradually drop to 18.2 percent of GDP at the end of 2021 from 23.9 percent at the end of 2017.
Bulgaria, which wants to adopt the euro currency, sees average EU-harmonised inflation picking up to 1.8 percent this year and 2.0 percent in 2019.
Under the index, Bulgaria's average inflation stood at 1.2 percent in 2017.